【面試準備】數據結構—樹

左孩子，右兄弟，二叉樹存儲-0-

#include <iostream>
using namespace std;
#include <stack>
#include <queue>

template<class T>
class TreeNode {
private:
	T data;
	TreeNode<T> *firstChild, *nextBrother;
public:
	TreeNode(T value, TreeNode<T> *L = NULL, TreeNode<T> *R = NULL) {
		data = value;
		firstChild = L;
		nextBrother = R;
	}
	TreeNode<T>* GetfirstChild() {
		return firstChild;
	}
	void SetfirstChild(TreeNode<T>* L) {
		firstChild = L;
	}
	TreeNode<T> * GetnextBrother() {
		return nextBrother;
	}
	void SetnextBrother(TreeNode<T> * R) {
		nextBrother = R;
	}
	T& Getdata() {
		return data;
	}
	void Setdata(T value) {
		data = value;
	}
};

template<class T>
class Tree {
private:
	TreeNode<T> *root;
public:
	Tree(TreeNode<T>* item = NULL) {
		root = item;
	}
	TreeNode<T> * Getroot() {
		return root;
	}
	void Setroot(TreeNode<T>* item) {
		root = item;
	}
	void Create(T stop_flag);
	TreeNode<T>* CreateTree(T stop_flag);
	TreeNode<T>* FindTarget(TreeNode<T>* t, T target); //在t爲根節點的樹中搜索值爲target的節點
	TreeNode<T>* FindFather(TreeNode<T>* t, TreeNode<T>* p); //在t爲根節點的樹中搜索p的父節點
	TreeNode<T>* FirstChild(TreeNode<T>* p); //返回p節點的左孩子節點
	TreeNode<T>* NextBrother(TreeNode<T>* p); //返回p節點的下一個兄弟節點
	void DelSubTree(TreeNode<T>* t, TreeNode<T>* p); //在t爲根節點的樹中刪除p爲根節點的子樹
	void Del(TreeNode<T>* p); //
	void PreOrder(TreeNode<T>* t); //先根、深搜
	void LevelOrder(TreeNode<T>* t); //層次、廣搜
	void PreOrder_N(TreeNode<T>* t);
};

template<class T>
TreeNode<T>* Tree<T>::FindFather(TreeNode<T>* t, TreeNode<T>* p) {
	if (t == NULL) {
		return NULL;
	}
	TreeNode<T>* result = NULL;
	TreeNode<T>* q = t->GetfirstChild();
	while (q != NULL & q != p) {
		result = FindFather(q, p);
		if (!result) {
			q = q->GetnextBrother();
		} else {
			return result;
		}
	}
	if (q == p) {
		return t;
	} else
		return NULL;
}

template<class T>
TreeNode<T>* Tree<T>::FindTarget(TreeNode<T>* t, T target) {
	if (t == NULL) {
		return NULL;
	}
	TreeNode<T>* result = NULL;
	if (t->Getdata() == target) {
		return t;
	} else {
		TreeNode<T>* q = t->GetfirstChild();
		while (q != NULL && (result = FindTarget(q, target)) == NULL) {
			q = q->GetnextBrother();
		}
		return result;
	}
}

template<class T>
TreeNode<T>* Tree<T>::FirstChild(TreeNode<T>* p) {
	if (p == NULL) {
		cout << "搜索節點爲空！" << endl;
		return NULL;
	}
	if (p->GetfirstChild()) {
		return p->GetfirstChild();
	}
	return NULL;
}

template<class T>
TreeNode<T>* Tree<T>::NextBrother(TreeNode<T>* p) {
	if (p == NULL) {
		cout << "搜索節點爲空！" << endl;
	}
	if (p->GetnextBrother()) {
		return p->GetnextBrother();
	}
	return NULL;
}

template<class T>
void Tree<T>::DelSubTree(TreeNode<T>* t, TreeNode<T>* p) {
	if (t == NULL || p == NULL) {
		cout << "根節點或p節點爲空！" << endl;
		return;
	} else {
		TreeNode<T> *q, *result;
		result = FindFather(t, p);
		if (result) {
			if (result->GetfirstChild() == p) {
				result->SetnextBrother(p->GetnextBrother());
				Del(p);
				return;
			} else {
				q = result->GetfirstChild();
				while (q->GetnextBrother() != p) {
					q = q->GetnextBrother();
				}
				q->SetnextBrother(p->GetnextBrother());
				Del(p);
				return;
			}
		} else {
			if (t == p) {
				cout << "t與p相同！" << endl;
				return;
			} else {
				cout << "p不在以t爲根的樹中！" << endl;
				return;
			}
		}
	}
}

template<class T>
void Tree<T>::Del(TreeNode<T> *p) {
	if (p != NULL) {
		TreeNode<T> *q = p->GetfirstChild(), *next;
		while (q != NULL) {
			next = q->GetnextBrother();
			Del(q);
			q = next;
		}
		delete p;
	}
	return;
}

template<class T>
void Tree<T>::PreOrder(TreeNode<T>* t) {
	if (t != NULL) {
		cout << t->Getdata() << endl;
		TreeNode<T>* child = FirstChild(t);
		while (child) {
			PreOrder(child);
			child = NextBrother(child);
		}
	}
	return;
}

template<class T>
void Tree<T>::LevelOrder(TreeNode<T> * t) {
	if (t != NULL) {
		queue<TreeNode<T>*> q;
		TreeNode<T>* p;
		q.push(t);
		while (!q.empty()) {
			p = q.front();
			q.pop();
			cout << p->Getdata() << endl;
			p = p->GetfirstChild();
			while (p != NULL) {
				q.push(p);
				p = p->GetnextBrother();
			}
		}
	}
	return;
}

template<class T>
void Tree<T>::PreOrder_N(TreeNode<T>* t) {
	if (t != NULL) {
		stack<TreeNode<T>*> s;
		TreeNode<T>* p = t;
		do {
			while (p != NULL) {
				cout << p->Getdata() << endl;
				s.push(p);
				p = p->GetfirstChild();
			}
			while (p == NULL && !s.empty()) {
				p = s.top();
				s.pop();
				p = p->GetnextBrother();
			}
		} while (!s.empty());
	}
	return;
}

template<class T>
TreeNode<T>* Tree<T>::CreateTree(T stop_flag) {
	TreeNode<T>* t, *t1, *t2;
	T item;
	cin >> item;
	if (item == stop_flag) {
		t = NULL;
		return t;
	} else {
		if (!(t = new TreeNode<T>(item))) {
			cout << "創建節點錯誤！" << endl;
			return NULL;
		}
		t1 = CreateTree(stop_flag);
		t->SetfirstChild(t1);
		t2 = CreateTree(stop_flag);
		t->SetnextBrother(t2);
		return t;
	}
}

template<class T>
void Tree<T>::Create(T stop_flag) {
	root = CreateTree(stop_flag);
}

int main() {
	Tree<int> *p = new Tree<int>;
	TreeNode<int> *q;
	p->Create(0);
	q = p->Getroot();
	p->PreOrder(q);
	cout << "*************" << endl;
	p->PreOrder_N(q);
	cout << "*************" << endl;
	p->LevelOrder(q);
	cout << "*************" << endl;
	TreeNode<int> * x;
	x = p->FindTarget(q, 7);
	cout << "11" << endl;
	cout << x->Getdata() << endl;
	;
	x = p->FindFather(q, x);
	cout << "11" << endl;
	cout << x->Getdata() << endl;
	p->DelSubTree(q, x);
	cout << "!11" << endl;
	p->LevelOrder(q);
	return 0;
}